You just led me to my next question. "smoothing" the surface of the sound path is affecting the sound (internal surface of the 2 horns) ?
Elias
Agree with your comments Scott but let's say we have a cabinet that doesn't introduce coloration, we still have the driver itself cause there's so many variation in cone materials so how do we arrive at what is none colored sound & realism & this excludes motor design etc. Would we not have to combine cabinet design, materials for a specific driver to create synergy & make it sing as one ?
Indeed! Folks migrated to Buzz's apartment thinking there was live music!
Mostly acoustic jazz recordings, early Nora Jones, Dave Brubeck, Jimmy Smith, John Coltrane, etc., along with then current Diana Krall CDs that mesmerized most. The real 'kicker' though was the 'dinky' little speakers (much tweaked 5.25" RS 30-1354 'FR' drivers) doing Ray Brown's/John Clayton's Super Bass CD at ~live venue SPL, though some was due to the apt's all concrete construction getting the most out of the MLTL's ''sharpness'.
Of course they wouldn't compete with multi-ways, etc., but these folks were mostly all young families with baby/young children used to 'el cheapo' mass market plastic systems at local big box stores and just couldn't get over how 'life-like' they sounded compared to the (usually) solo artist at the local pizza/whatever bar on Saturday night.
Cool! Though her way only works with horns like the Victor and other brands used; for square, rectangular boxes it's the odd harmonic eigenmodes, though of course doesn't mean her speakers don't perform as good as practical if the driver/vent happen to be near/at an odd harmonic.
It's not my place to comment on other people's designs, but from a generalised perspective, smoothing internals promotes maximum efficiency at the top end of the horn's gain BW, while having comparatively little effect lower down the range (as you'd expect given the wavelengths involved). As back-loaded (bass) horns goes, I generally view it as counter-productive as I want a faster acoustic low-pass to keep GD down and the response as linear as possible within a given context of design detail. That's why I design my own to use the folding scheme as a functional part of that acoustic low-pass. Front [loaded] midrange / HF horns are a completely different matter of course. 😉
Not to me, but I've never claimed home audio is proscriptive. 😉 With my personal hat on though, from a design POV the last thing I want is panels adding random colourations that have absolutely nothing to do with the original signal. I basically want the box structure to have zero contribution to the net sound at the listening position, with what you hear being a combination of the driver's innate response characteristics in association with the amplifier's output impedance and (as relevant) the enclosure alignment, and (hopefully minimised) room effects. There's enough within that little lot for me to be going on with.
Adding some grs of weight to the moving mase of a full range ? What about the top end of the spectrum ? The special composition paper cone with mica isn't stiff enough ?
Elias
The forum search facility is your friend. 😉
Short version: EnABL is a form of cone modifications which employs adding several rings of blocks (usually via some form of paint, but other methods could be used) to different points on the driver cone or other emitting surfaces. Originally it assumed adding these rings at specific geometric locations consistant across all cones & covering then ensemble with a conformal coating. Added mass was minimal, inherently varying with cone size but rather less than 1g for a small type -this is not heavy material slathered on but tiny quantities added at specific points, with an overall coating thickness akin to what you'd get via a single light pass from a rattle-can. Latterly the positioning of thise block rings was determined via empirical testing of significant cone resonant modes, and they were positioned at those points instead, while the additional conformal coating did not always get used -this change being carefully 'forgotten' by many who objected to the original more generic implementation and the theory behind it. Changes could be difficult to assess, although the more recent implementations certainly make mechanical sense.
Short version: EnABL is a form of cone modifications which employs adding several rings of blocks (usually via some form of paint, but other methods could be used) to different points on the driver cone or other emitting surfaces. Originally it assumed adding these rings at specific geometric locations consistant across all cones & covering then ensemble with a conformal coating. Added mass was minimal, inherently varying with cone size but rather less than 1g for a small type -this is not heavy material slathered on but tiny quantities added at specific points, with an overall coating thickness akin to what you'd get via a single light pass from a rattle-can. Latterly the positioning of thise block rings was determined via empirical testing of significant cone resonant modes, and they were positioned at those points instead, while the additional conformal coating did not always get used -this change being carefully 'forgotten' by many who objected to the original more generic implementation and the theory behind it. Changes could be difficult to assess, although the more recent implementations certainly make mechanical sense.
Scott
I have seen this "EnABL" at the drivers that are treated from Dave. So thanks for the clarification.
"playing" with my daughter's liquid enamel I feel that it is a heavy material (at least according to my very sensitive scale). Some vintage drivers I own (10") with "plastic" cone are really "flexing" too much. Mainly at very low frequency punchy bass beat at high power (About 50W) But CHP-90 cone is very stiff (also some other drivers I own, from 2,5" ~ 4" with carbon fiber cone or glass-fabric cone). I touch it (them) and I feel it. I have seen in youtube thin paper or "plastic" cones waving horribly (looks like a standing wave traveling round around the cone suspension). So I repeat the question. Does CHP-90 really needs that treatment ?
Elias
I have seen this "EnABL" at the drivers that are treated from Dave. So thanks for the clarification.
"playing" with my daughter's liquid enamel I feel that it is a heavy material (at least according to my very sensitive scale). Some vintage drivers I own (10") with "plastic" cone are really "flexing" too much. Mainly at very low frequency punchy bass beat at high power (About 50W) But CHP-90 cone is very stiff (also some other drivers I own, from 2,5" ~ 4" with carbon fiber cone or glass-fabric cone). I touch it (them) and I feel it. I have seen in youtube thin paper or "plastic" cones waving horribly (looks like a standing wave traveling round around the cone suspension). So I repeat the question. Does CHP-90 really needs that treatment ?
Elias
That ultimately depends on how you define 'need', and exactly what modifications you make so unfortunately there's no single answer to that.
Ignoring specifics, all drive units have concentric waves radiating out from the coil, meeting and to some degree reflecting back from the edge-termination of the surround. In many (most) cases you won't actually see them under use, but these & other TL modes through the cone, and the controlled bend / resonance of the substrate are how most wideband drive units produce a significant portion of their BW. Any kind of change to the substrate will affect this, the details varying with exactly what is done.
Ignoring specifics, all drive units have concentric waves radiating out from the coil, meeting and to some degree reflecting back from the edge-termination of the surround. In many (most) cases you won't actually see them under use, but these & other TL modes through the cone, and the controlled bend / resonance of the substrate are how most wideband drive units produce a significant portion of their BW. Any kind of change to the substrate will affect this, the details varying with exactly what is done.
When I was younger, I tried brushing diluted Araldite on paper cones. The sound ended up being more homogeneous.
Unfortunately, details were lost. I probably painted on too much so the cone was too heavy. If you listen to one without and with, you hear a clear difference.
You can.
Thing about all these modifications is that, ideally, they need to be specifically targeted to the driver for best results. That's in essence how EnABL ended up (though it started in a much more generic sense). Generics can be useful in some cases, but it's a bit of a shotgun approach & there's no guarantee you'll either fix what you want to address, or do so without causing an issue elsewhere.
Every time you make additions to the cone you're adding mass (natch) and thereby some mechanical damping -how much depending on quantity. But the actual effects also depend on whether you add this at specific points on the substrate, as an overall coating, or some combination of the two. If adding at specific locations, in that sense it's akin, though not exactly the same, as varying the cone thicknesses at different positions. Scan's slit paper Revelators are another variation; Bozak's old cones with their rough, randomised rear surface were another (whether by accident or original design), Fostex's ESigma range (or Olson's LC-1A for that matter) still another, adding aluminium foil etc. yet another, & so on & so forth. You might, say, add damping at the periphery of a paper or other 'soft' cone to damp its edge-resonance, where it can cause a cancellation by flobbering about & going into antiphase, or a ring at x point about the cone to damp the amplitude of a mode centred at that point. Or a set of blocks which may modify the behaviour of the transverse wave in a more subtle fashion. And that's before you get to the question of the materials themselves, since these too can / will make a difference to the end-results, because while adding even small quantities of mass can make a significant difference to a TL mode (without necessarily raising Mmd sufficiently to have a significant impact on overall efficiency) some materials will have the effect of increasing rigidity, which will in turn also modify the resonant behaviour. Lots of fun to be had, if you've the time & inclination. I never really had the patience myself to do more than some basic tweaks, but I admire those who can & do achieve much more.
Thing about all these modifications is that, ideally, they need to be specifically targeted to the driver for best results. That's in essence how EnABL ended up (though it started in a much more generic sense). Generics can be useful in some cases, but it's a bit of a shotgun approach & there's no guarantee you'll either fix what you want to address, or do so without causing an issue elsewhere.
Every time you make additions to the cone you're adding mass (natch) and thereby some mechanical damping -how much depending on quantity. But the actual effects also depend on whether you add this at specific points on the substrate, as an overall coating, or some combination of the two. If adding at specific locations, in that sense it's akin, though not exactly the same, as varying the cone thicknesses at different positions. Scan's slit paper Revelators are another variation; Bozak's old cones with their rough, randomised rear surface were another (whether by accident or original design), Fostex's ESigma range (or Olson's LC-1A for that matter) still another, adding aluminium foil etc. yet another, & so on & so forth. You might, say, add damping at the periphery of a paper or other 'soft' cone to damp its edge-resonance, where it can cause a cancellation by flobbering about & going into antiphase, or a ring at x point about the cone to damp the amplitude of a mode centred at that point. Or a set of blocks which may modify the behaviour of the transverse wave in a more subtle fashion. And that's before you get to the question of the materials themselves, since these too can / will make a difference to the end-results, because while adding even small quantities of mass can make a significant difference to a TL mode (without necessarily raising Mmd sufficiently to have a significant impact on overall efficiency) some materials will have the effect of increasing rigidity, which will in turn also modify the resonant behaviour. Lots of fun to be had, if you've the time & inclination. I never really had the patience myself to do more than some basic tweaks, but I admire those who can & do achieve much more.
There is time, desire too. But I'm afraid it will get worse. Are there any changes you can make that are harmless and can't destroy?
Only reversible ones. 😉 Where relevant the $0.99 tweak & variations thereof for whizzer cone drivers for example. Tiny felt dots or similar with some kind of removable adhesive that doesn't stain or cause damage would be another.
Otherwise -electrical manipulation. In that ideal world we all hear tell of, mechanical solutions to mechanical problems are likely to provide the best results. If you're in the same world I am, where that famous creek resides we go up and lose our paddles, it's not always practical, and while they aren't a panacea, passive or active electrical filters at least mean you haven't permanently damaged or altered the driver in a way you subsequently regret.
Otherwise -electrical manipulation. In that ideal world we all hear tell of, mechanical solutions to mechanical problems are likely to provide the best results. If you're in the same world I am, where that famous creek resides we go up and lose our paddles, it's not always practical, and while they aren't a panacea, passive or active electrical filters at least mean you haven't permanently damaged or altered the driver in a way you subsequently regret.